Sea anemones (Cnidaria: Actiniaria) of Singapore: shallow-water species known also from the Indian subcontinent

We document for the first time five species of intertidal and shallow subtidal sea anemones (members of cnidarian order Actiniaria) from the Republic of Singapore. Bunodosoma goanense den Hartog & Vennam, 1993, Pelocoetes exul (Annandale, 1907), and Stephensonactis ornata Panikkar, 1936, were previously known only from India; they occur primarily on the north (Johor Straits) side of Singapore. Actinoporus elongatus Carlgren, 1900, and Paracondylactis sinensis Carlgren, 1934, which occur primarily on the south (Singapore Straits) side of Singapore, have been reported from India and elsewhere. In addition, we discuss Cancrisocia expansa Stimpson, 1856, a subtidal species that occurs in the Johor Straits, and that has been known mainly from East Asia and in the crustacean literature because it is symbiotic with the crab Dorippoides facchino. We confirm that C. expansa belongs to family Actiniidae, not to family Sagartiidae, and distinguish it from Paraiptasia radiata, a sea anemone un-named in a report from India; this species, the most widespread we have recorded in Singapore, has been known only in east Asia as far west as Singapore. Metapeachia tropica (Panikkar, 1938), which also occurs in both Singapore and the Indian subcontinent, is the subject of a separate publication.